1. Field of the Invention
The present invention relates to orthopedic devices for improving lower-extremity mechanics.
2. Description of the Related Art
Many people suffer from abnormal motions of the patella. There are several basic types of abnormalities that may occur with the patella: it may dislocate (slip out of place), sublux (partially slip out of place), fracture, develop degenerative arthritis, or develop a tracking problem. A tracking problem describes a patella that stays in place in front of the knee, but no longer remains centered in the front part of the femur known as the trochlear groove.
When tracking problems occur, the kneecap develops an abnormal set of biomechanics that results in abnormally increased pressure on the underside of the patella (patellar articular surface). The pain that results from this condition has a variety of different names, but all of these diagnoses refer to a biomechanical abnormality of the joint space between the patella and the trochlear groove of the femur. Normally, the patella sits centered in the groove.
One conventional treatment for patellar tracking problems comprises fitting the sufferer with an external brace. Many of these braces apply force directly to the patella in order to maintain it within the trochlear groove and to force it to follow the proper tracking path. For example, U.S. Pat. No. 4,296,744 to Palumbo discloses a dynamic patellar brace for both diagnosis and treatment of patellar subluxation. The brace includes a patellar bracing pad adapted to be positioned laterally with respect to the patella. The pad applies medially-directed pressure to the patella to help prevent subluxation.